Key changeable tumbler construction for combination locks



June 4, 1968 A. J. PQTZICK 3,386,275

KEY CHANGEABLE TUMBLER CONSTRUCTION-FOR COMBINATION LOCKS 5 3g y Waff/vifs n. Ju'ne 4, 1968 A. .1'. PoTz|cK 3,385,275

KEY CHANGEABLE TUMBLER CONSTRUCTION FOR COMBINATION LOCKS AFiled Feb. 1A. 1966 2 Sheets-Sheet 2 United States Patent O 3,386,275 KEY CHANGEABLE TUMBLER CONSTRUCTION FOR COMBINATION LGCKS Anthony I. Potzick, Cincinnati, hio, assignorto The Mosler Safe Company, Hamilton, Ohio, a corporation of hio Filed Feb. 14, 1966, Ser. No. 527,371 14 Claims. (Cl. 70--316) ABSTRACT F THE DISCLOSURE A key changeable tumbler construction wherein, in preferred form, a center disk is releasably connected to a gate-presenting outer ring by a circular spring. The spring is mounted to the outer ring for rotation therewith and is displaceable, by a cam, in the direction parallel to the axis of the center disk, toward and away from the center disk. When rotated, the cam bends a portion of the spring into interlocking engagement with the center disk, so that the center disk is then coupled to the outer disk for ordinary lock operation. When the key-operated cam is turned in the other direction the spring is uncoupled from engagement with the center disk, so that the outer ring is released and can be rotated relative to the center disk to change the combination.

nam- This invention relates to combination locks and is particularly directed to a key changeable tumbler construction for use in such locks.

In the normal use of a combination lock, it often becomes necessary to change the lock combination. Actually, it is standard operating procedure in many areas of business and government to change the lock combination at frequent intervals for security reasons, even as often as once a day. Changes in personnel and the possibility of unauthorized access to the combination, among other reasons, dictate change of the lock combination.

In conventional combination locks employing rotatable tumblers, the lock combination has usually been changed by opening the lock case, taking the tumbler mechanism apart, resetting the angular position of each tumbler gate with respect to the tumbler drive pin thereby resetting the position of the gate with respect to the dial, reassembling the tumblers and replacing them in the lock case. Of course, this mode of changing the combination usually requires the efforts of a locksmith and certainly is no practical answer to the lock operator who wants to effect such a change immediately, conveniently, and often frequently. As a consequence, lock constructions which provide convenient and efticient means of changing the lock combination are needed to meet the normal operational requirements for such usage.

It has also been proposed to provide tumblers with externally actuated mechanisms for effecting a resetting of the combination, for example by means of a special tool or key. Such key changeable tumbler mechanisms are usually actuated by a key which is inserted through an aperture provided in the back plate of the lock case. The key uncouples an outer tumbler gate portion from an inner portion, thereby permitting the angular position of the dial relative to one or more tumbler gate portions to be changed without disassembling the lock.

While the key changeable tumblers previously in use have aiforded convenience to the operator, they have been lacking in other respects. In particular, earlier key changeable tumbler constructions have been subject to surreptitious attack by radiographic means whereby the tumbler gate position can sometimes be determined through X-ray photographs of the lock taken through the 3,386,275 Patented June 4, 1968 ice safe or tile. Such tumblers have tended to lend themselves to forming rather sharp X-ray images on which the relative angular positions of the gates at a given dial position can be ascertained.

Other proposed constructions have not provided sufficiently positive mechanism for determining or holding the preselected position of the various inter-adjustable portions of the tumbler with the result that undesirable relative movement 0f the tumbler gates has sometimes occurred in use. Those constructions which have sought to avoid these problems have employed additional features which further complicated the structures and increased their cost.

In view of the prior art constructions, there has been a continuing need for a key changeable tumbler construction which is not susceptible to radiographic and radiologic attack, and which further provides a positive locking mechanism for selectively and securely coupling and uncoupling the relatively movable tumbler portions, yet which is as easy to operate as previous constructions. An objective of this invention has been to provide a tumbler construction which will fulll this need, and at an acceptable cost.

In accordance with this invention, a tumbler construction is provided which includes key operated means for shifting, springing, or bending a clamp element in a direction parallel to the tumbler axis, to selectively bring the clamp element into and out of locking engagement with a center disk which is rotatably mounted with respect to surrounding outer means. By this means the center disk and outer means are coupled for normal operation and are uncoupled for changing the combination, respectively.

A preferred tumbler construction according to this invention comprises a center disk which is cooperable in driven and driving relation with the driver and the other tumblers of the lock, a composite outer ring mounted on and rotatable about the center disk, an annular clamp ring connectable between the center disk and the outer ring by partial or non-uniform axial movement therebetween to lock the disk and outer ring in angularly adjustable positions, and a key operated cam having a cam track engaging a portion of the clamp ring for axially shifting the clamp ring into locking engagement between the disk and outer ring thereby coupling the n'ng and disk together as a unit for normal operation and for selectively shifting the clamp ring out of such locking engagement to permit the combination to be changed.

The operation and details of the invention can best be further described by referring to the accompanying drawings in which:

FIGURE 1 is a perspective view `of an illustrative key changeable combination lock environment in which the tumblers of this invention are used, and is partly broken away to illustrate the lock mechanism.

FIGURE 2 is a enlarged fragmentary cross-section, partly broken away, of a lock mechanism of the type shown in FIG. l, illustrating an assembly `of tumblers each having the preferred tumbler construction of this invention and showing the key in place for changing the combination of the lock with the clamp rings engaged with the respective center disks.

FIGURE 3 is a fragmentary cross-sectional view of a single tumbler, illustrating the cam track and showing the clamp ring in disengaged relation with the center disk.

FIGURE 4 is an exploded view in perspective of the tumbler elements, illustrating the top pla-te, fly, center disk, clamp ring, rotatable cam or locking means, and the bottom plate.

yThe lock environment for the key changeable tumblers of this invention shown in FIGURE l for purposes of illustration comprises a combination lock mechanism 1 lwhich is contained in a case 2 mounted on the inside of a safe or iile door 3. The mechanism includes three tnmblers, designed as 4, 5 and 6, which may be identical. The tumlers, each separated by a brass ring or washer 7, are rotatably mounted on a boss or sleeve 9 (as shown more clearly in FIGURE 2) which may be formed on the cover or back plate 10 of case 2. In a position adjacent to and overhanging the peripheral edges of the tumblers, fence 11 projects from an angle bar or lever 12 which is connected to operate a bolt 13. Each tumbler 4, 5, and 6 has a peripheral gate 15, and in FGURE 1 the lock is shown with these gates 15 aligned and the fence 11 seated in them.

The several tumblers d, 5 and 6 are rotationally interconnected through a series of lost motion slots and pirr couplings (shown generally at 16 in FIGURE 2) to each other and to a driver 17. The driver is operated through a conventional arbor or shaft 18 which is connected to a rotatable dial (not shown) on the outside of the door 3.

When the combination is to be changed, a key 22- having an asymmetric or groeved shank 23 is engageable, through an aperture 24 in the back plate 18 of case 2, with keyholes in each tumbler 4, 5 and 6 when they are aligned at the position shown in FIGURE 2. When the tumblers are in proper alignment for changing the combination, fence 11 does not engage gates 15; and conversely, when the fence does engage the gates for opening the lock, the key 22 cannot engage the tumbler keyholes, as shown in FIG. 1.

Referring now to FIGURE 4, the preferred construction of the key changable tumblers 4, 5 and 6 in accordance with this invention will be described in detail. Each tumbler includes an inner first element or center disk 26 having a rib 27 around its peripheral edge surface in which teeth, lugs, or serrations 28 are formed. On opposite sides of rib 27 annular shoulders 29 and 30 are `formed in disk 26 for rotatably engaging an annular top plate 31 and an annular bottom plate 32, respectively, which together define a second element or composite outer ring 33.

As shown in FIGURE 2, the center disk 26 has an axial opening 36 adapted for journalling the tumbler on sleeve 9 of the lock mechanism 1. Also formed in the center disk 26, on opposite sides thereof, are a drive pin 37 for transmitting rotational movement to an adjacent tumbler, and a lost motion slot 38. The lost motion groove 38 is defined on the face of center disk 26 between an inner rib or wall 39 around opening 36, and shoulder 29.

A generally ring-like fly 41 is rotatably received in lost motion groove 38, between rib 39 and shoulder 29. Fly 41 has a radially projecting lug or stop 42 which extends through a space 43 in the discontinuous periphery of shoulder 29. In use, one or the other radial side faces of fly lug 42 is engaged by the drive pin 37 of an adjacent tumbler or by the drive pin 45 of the driver. Since the lug can move only within the opening 43 in shoulder 29, motion imparted to the lu g will be taken up and then transmitted to turn the center disk on sleeve 9.

As will be understood by those skilled in the art, the use of a fly is conventional in tumbler constructions and forms no part of the present invention. In place of a fly, the center disk may simply have a fixed lug or stop in groove 38 for engagement by the drive pin, although this will reduce the total number of different combinations to which the lock can be set to operate.

As mentioned above, the composite outer ring 33 is formed by the top plate 31 and the bottom plate 32. Bottom plate 32 has facial tongues or ribs 46, 46 which fit and are secured into cooperating grooves or recesses 47, 47 in the top plate 31 for holding the plates together. The plates 31 and 32 are provided with bearing holes 50 and 51, respectively, which rotatably engage the annular shoulders 29 and 30, respectively, formed on the center disk 26 on each side of rib 27. The top plate 31 is provided with an annular internal recess or surface 52 adapted to bear facially on the side surface 53 of the disk rib 27. Top plate 31 also has a short arcuate facial recess 55 which is formed in the interior face or bearing surface 56 inwardly of the `grooves 47, 47 therein.

As shown more clearly in FIGURE 3, bearing surface 56 is adapted to engage one side surface 57 of coupling means in the form of a clamp ring or coupler 58 and to preclude axial movement of the proximate portion of the clamp ring between the two plates 31 and 32.

The bottom plate 32 has an annular internal recess 60 formed therein `for seating the annular clamp ring 58. A series of pins or studs 61-are formed around internal recess 60, and these pins cooperate with holes 62 on the clamp ring 53 to preclude rotation of the clamp ring 58 relative to the composite outer ring 33. However, no pins are provided on an arcuate segment 65 of bottom plate 32, corresponding to the recess 55 of the top plate 31, in order not to impede relative axial movement of an elementinterlocking portion or segment 66 of clamp ring 58 which in the assembled tumbler is between recess 55 and segment 65.

Aligned internal seating cam recesses or journals 67 and 68 are formed in plates 31 and 32, respectively, for rotatably supporting a cam 71. Bearing holes 72 and 73 are formed in the bottoms of the cam recesses 76 and 68, respectively, for rotatably engaging bearing portions of the rotatable cam 71. The cam recesses 67 and 68 extend radially into or intersect the annular internal recess 55 of top plate 31 and the open portion 65 of bottom plate 32. Aligned notches or cutouts 74 and 75 are formed in the peripheral edges of plates 31 and 32, respectively, and when the plates are assembled these notches provide the tumbler gate 15 which cooperates with the conventional fence 11 of the angle bar 12.

The resilient annular ring 58 comprises a clamp means for locking the center disk 26 and composite outer ring 33 in angularly adjustable positions. The clamp ring 58 is adapted to be loosely received in the annular recess 60 of the bottom plate 32 with pins 61 engaged in holes 62 formed in the clamp ring to preclude rotation of the clamp ring relative to the composite outer ring 33, While at the same time permitting limited axial movement. The clamp ring has serrations or teeth 77 formed in its inner edge 78 which are adapted to lbe selectively engaged with a segment of the serrations 28 on the center disk 26.

A rotatable actuating means for shifting or bending the clamp ring 58 in the axial direction comprises the cylindrical cam element 71 having a central edge surface 80 journalled in the cam recesses 67 and 68 of plates 31 and 32 respectively. Cam 71 has coaxial end bearing portions 81 and 82 on each side of the central portion 88, and these portions y81 and 82 are rotatably engaged in holes 72 and 73, respectively, formed in plates 31 and 32, respectively. An asymmetric hole 84 is formed axially through the cam for receiving the shank 23 of actuating key 22 when properly oriented. The peripheral edge surface 80 of the cam is provided with a detent notch 85 which is adapted to engage a detent `86 formed in recesses 67, 68 of the plates 31, 32 respectively. A continuous cam surface or track 87 is formed skew to the axis of cam 71 in the central edge portion 80 of the cam and is adapted to engage the outer periphery y88 of clamp ring 58. Cam 71 is operable to selectively bend the chordal portion 66 of clamp ring 58 out of a flat plane, thereby moving axially a portion of the clamp ring serrations 77 to engage a portion of the center `disk serrations 28 (as shown in FIGURE 2) and coupling the composite outer ring means 33 to the disk so that the tumbler will rotate as a unit.

It is preferable that the outer ring 33, the center disk 26, and the cam 71 be made of a material having a low radiographic density such as the polycarbonate plastic Lexan, produced by General Electric. Use of such material in the construction described makes it difficult to determine the relative position vof the tumbler gate by X- raying the lock. For the same reason there may be formed a number of false gates around the periphery of either or both of the plates 31 and 32, which under X-ray examination Will appear confusingly similar to the one true gate 15. False cams may also be incorporated to hinder detection of the real gate by reference to the position of cam 71. Clamp ring 58 should -be made of a resilient spring material such as phosphor bronze so that it will return undetormed to a -at plane when cam 71 permits it to do so.

Use of a thermoplastic material vfor the top and bottom plates permits them to be easily assembled as the integral unit 33 with the clamp ring mounted between them. To that end pins 61 and tongues 46, 46 may be provided with pointed or ridged surfaces for engaging top plate 31 in initial assembly. Upon heating, or under the effect of ultrasonic vibrations, the top and bottom plates will be securely bonded together.

The lock 1 shown in the drawings includes a shutter or mask mechanism as designated generally at 90 in FIGURE 2, for permitting only rapid snap action contact between the fence 11 and the tumblers 4, 5, and 6. Such mechanism forms the subject of my Patent No. 3,073,145, issued January 15, 1963, and forms no part of this invention although it is a desirable adjunct in commercial practice.

The lock 1 may also include optional arbor vibration dumping means, shown generally at 91, which reduce the transmission of vibrations through the arbor, making manipulation based on detection of such vibrations more diicult. The means 91 are described and claimed in R. W. Maynard Patent No. 3,106,083, issued Oct. 8, 1963, to which reference is hereby made, and comprise no part of the present invention.

The operation of the key changeable tumblers of this invention may now be described with reference to the overall lock environment. The dial of the lock is rotated to turn the driver 17 which is connected to the dial through the operating shaft or arbor 18. Turned in accordance with the proper combination, driver pin 4S operates the rotatable tumbler -6 which in turn sequentially operates tumbler 5, etc., through the series of lost motion interconnections 16 to bring all of the tumbler gates 15 into alignment with each other at the proper angular position adjacent the fence 11. When this has been done, and a conventional driver notch (not shown) is aligned for making engagement with the angle bar nose, fence 11 can drop into the gates of the tumblers. This permits the angle bar 12 to be operatively engaged by the driver. The bolt 13 can then -be withdrawn from its locking position by further rotation of the lock dial.

During this normal operation of the lock, each tumbler center disk 26 is locked or interengaged with its respective composite outer ring 33 for operation as a unit. In such interlocking relation, cam track 87 holds a portion 66 of the annular clamp ring in a position axially shifted out of the general plane of the clamp ring. Several clamp serrations 77 are thereby engaged with the center disk serrations 28. Surface 56 of the top plate prevents the axial displacement of the entire clamp ring 58 (see FIG- URE 3). The clamp ring is precluded from rotational movement relative to the tumbler outer ring 33 by the pins 61 which are sockcted in holes 62 of the clamp ring. The rotatable cam 71, in its normal position, is tixed with respect to the outer ring 33 by the stressing forces and by detent `86 which engages detent notch IS5.

The tumbler keyholes or cam holes 84 are preferably uniformly displaced from aperture 24 in the back plate 10 when the tumblers are aligned for opening the lock. Hence, when the combination is to be changed, the combination is run and the lock is opened in the conventional manner but with a specified, predetermined fixed number added to each number of the combination. This brings all the cam holes 84 into alignment opposite aperture 24 so that key shank 23 can be inserted into engagement with the cams. Because of the unique shape of the key shank 23, all the cams 71 must be in the same angular position before the key can be inserted. The key is then turned to simultaneously release all the center disks 26 from their respective outer rings 33, snapping each detent 86 out of engagement with its respective detent notch 85. As the key is turned from its initial position, each cam track 87 cams the normally displaced portion 66 of the clamp ring 58 back into its general plane so that each ring 58 is entirely seated in the recess 60 in plate 32. In this position, the clamp serrations 77 are disengaged from the center disk serrations 28 and each center disk 26 can be rotated about its axis relative to its outer ring 33. The dial numbers can now be reset simply by running the new combination with the additive constant, in the known manner. This correspondingly realigns each center disk with respect to its outer ring 33. The key is then turned 180, to its initial position, thereby relocking the clamp ring and outer disks, and the setting of the new combination is complete.

By reason of the axial movement required to unlock the center disk from the outer ring, the tumbler can better resist the tangentially directed forces acting on the tumbler in use which tend to turn the outer ring relative to the center disk, as compared with previous key changeable tumbler constructions in which the coupling has been effected by movement within the general plane of the tumbler. Moreover, the low mass of the components and the radial journals between them permits relative motion to be readily transmitted during combination changing.

Having described my invention, I claim:

1. A tumbler for a combination lock comprising,

a tirst element, said irst element having an axis of rotation,

a second element having a fence-receiving gate,

means supporting said second element for rotation relative to said first element about said axis,

coupling means mounted by one of said irst and second elements for rotation therewith,

said coupling means having an element-interlocking portion which is movable, with respect to said one of said elements, in a direction parallel to said axis to an interlocking position in which it is interlocked with the other of said rst and second elements so that said elements are \coupled together for rotation as a unit about said axis,

and a rotatable cam,

said cam having a cam surface thereon which is engageable with said element-interlocking portion of said coupling means,

said cam surface being so shaped that when said cam is rotated, said cam surface engages and cams said interlocking portion in said direction parallel to said axis into said interlocking position.

2. The tumbler of claim 1 wherein said first element comprises a disk and said second element comprises an annular ring encircling said disk and journalled by said disk for rotation about the .axis of said disk.

3. The tumbler of claim 2 wherein said annular ring comprises two separate portions engaging opposite surfaces presented by said disk.

4. The tumbler of claim 3 wherein said coupling means comprises an annular spring which is clamped between said two portions of said ring except for `a chordal segment of said spring which comprises said interlocking portion.

5. The tumbler of claim 4 wherein said cam has opposite end portions journalled in the two portions of said annular ring and has a cam track formed in an intermediate edge surface between said end portions for engaging said spring.

6. The tumbler of claim 1 wherein said coupling means comprises a spring constantly engaging said second element and resiliently bendable in a direction parallel to said axis over said interlocking portion thereof by said cam to engage and disengage said first element and thereby respectively couple and uncouple said rst and second elements.

7. The tumbler of claim 6 wherein said spring is in the form of an annulus having serrations on an edge thereof, and wherein said first element has an edge presenting serrations cooperable with the serrations of said spring to lock said first and second elements together.

8. The tumbler of claim '7 further wherein said cam is journalled by said second element and said cam surface engages an outer edge portion of said spring to displace said edge portion relative to the remainder of said spring and into engagement with said first element.

9. A key-changeable tumbler construction comprising,

a center disk,

a gate-presenting member mounted by said disk for rotation relative to said disk,

a coupler connected to said member for rotation therewith and supported by said member for limited iovement toward and away from said disk in the direction parallel to the axis of said disk, interengageable means provided by and between said disk and said coupler for interengaging said coupler to said disk when said coupler is moved suiciently toward said disk, and a key-operated cam mounted by said member,

said cam being rotatable with respect to said member about an axis parallel to the axis of said center disk,

said cam having a cam surface thereon which engages said coupler and which, when said cam is rotated one way about its axis of rotation, cams said coupler in said direction parallel to the axis of said disk a distance suiiicient to interengage said interengageable means of said disk and coupler, and which, when said cam is rotated the opposite way about its axis, moves said coupler oppositely a distance sufficient to disengage said interengageable means of said disk and coupler.v

10. The tumbler construction of claim 9 wherein said member is in the form of a ring journalled on said disk.

11. The tumbler construction of claim 9 wherein said coupler comprises a spring in the form of annulus.

12. The tumbler construction of claim 11 wherein said interengageable means comprise teeth on said spring interlockable with teeth on said disk.

13. The tumbler construction of claim 11 wherein said key-operated cam has a peripheral cam groove constantly engaging an edge portion of said spring for camming only said portion by bending said edge portion in said direction parallel to the axis of said disk.

14. The tumbler construction of claim 13 which further includes a detent for locking said cam in the position thereof at which said spring is interengaged with said disk.

References Cited UNITED STATES PATENTS 1,520,092 12/1924 Shaler 70-26 1,928,853 10/1933 Doenges 70-323 1,092,874 4/1914 Taylor 70--317 1,644,650 10/1927 Millice 70--316 MARVIN A. CHAMPION, Primary Examiner.

ROBERT L. WOLFE, Assistant Examiner. 

